Fractional Quantum Hall states Under Decoherence

Zijian Wang studies how dephasing affects Laughlin and Moore–Read quantum Hall states and their ability to store quantum information. Plasma analogies and field theory reveal two regimes separated by a critical filling: below it, finite noise causes a Berezinskii–Kosterlitz–Thouless transition and degrades the encoded memory; above it, memory survives until infinite noise. The critical filling is one quarter for Rényi-2 and lies between one quarter and one eighth in the replica limit. For Moore–Read states, the transition also governs whether non-Abelian fusion outcomes remain distinguishable.